Preterm birth (PTB), delivery prior to 37 weeks gestational age, accounts for 11.4% of all births and remains the leading cause of neonatal death. The majority of PTB is preceded by spontaneous preterm labor (PTL). Currently, there is a major unmet need for methods to identify women at risk of PTL and provide an early warning system for potential intervention. home uterine monitoring (HUM), is one approach that has shown some promise as an early warning system for PTL. However, a critical limitation of HUM relies on bulky, and wired equipment. Thus, this system only allowed for transient monitoring in a sedentary state (<2 hours per day). Furthermore, older HUM trials utilized tocodynamometry (pressure). Newer evidence suggests that electromyography (EMG)-based measurements for uterine activity offer superior predictive power and are less influenced by body habitus. Although continuous measurement of other physiological parameters such as heart rate, heart rate variability, sleep efficiency, temperature, and blood pressure may hold additional predictive value for spontaneous PTL beyond uterine monitoring alone, the predictive ability of the combination of these measures has not been evaluated. The ability to cost-effectively, comprehensively and continuously measure a variety of physiological parameters in the home setting, and relate these parameters to spontaneous PTL, remains unexplored. In this proposal, we will modify our existing wireless, ultra-thin, flexible, and miniaturized vital signs monitoring system?composed of a time-linked chest patch, limb patch, and abdominal patch (<2 mm in thickness)?for home use. The chest unit includes a 1-lead ECG (heart rate), accelerometer (physical activity, sleep quality, respiration), and temperature sensor. The limb patch incorporates a photoplethysmograph (PPG for SpO2). Together, the chest and limb sensor is able to provide a non-invasive continuous measurement of blood pressure (BP) by calculating pulse arrival time (PAT). Lastly, the abdominal patch unit includes an ultra-low noise continuous EMG for the continuous sensing of uterine contraction frequency, amplitude and propagation velocity. These sensors can be applied without the presence of a health care profession (e.g. analogous to applying a bandaid). We hypothesize that a low-burden, wireless, and wearable monitoring system that allows continuous measurement of multiple physiologic parameters will allow improved and earlier detection of PTL in high-risk women.